The present invention relates generally to a heating apparatus, and more particularly to an indirectly heating type of an electric boiler capable of operating at a high efficiency using less energy.
In a conventional boiler, a heating medium or water is directly heated by a heating unit, and the heated water or a high temperature heating medium is fed to a hot water pipe by means of a circulating pump. Such a type of the boiler has some disadvantages as followings.
The boiler adopts an electric heater or burner in order to heat the fluid medium. The fluid medium is directly heated by the heat generated from the electric heater or burner, so that the efficiency of the boiler is not high relative to the input quantity of energy.
More specifically, the fluid medium or water is in contact with the electric heater, and so the fluid medium boils on a surface of the electric heater. When the fluid medium is boiling, bubbles are generated, such that the bubbles prevents the heat transfer of the electric heater from being transferred to the fluid medium. Accordingly, although the boiler uses a lot of energy, it operates at lower efficiency. Also, in case of the burner, since the water or fluid medium in a heating tube heated by a burner boils, the above problem is happened.
Therefore, it is necessary for the conventional boiler to exhaust periodically the bubbles produced in the hot water heating unit and the hot water pipe. In addition, when the water or fluid medium flows in the hot water heating unit and the hot water pipe, a noise or vibration is happened. If the bubble is not exhausted periodically, the efficiency of the boiler is decreased rapidly, thereby causing the trouble of boiler.
In addition, because the hot water or heated fluid medium is rapidly cooled simultaneous with the shut-off of the power, a lot of energy has to be used to heat the fluid medium again.
As described above, because the conventional boiler heating directly the fluid medium produces the bubbles due to the boiling effect of the fluid medium, if a diameter or volume of the heating tube is small, the heat of the heating member is not transferred to the fluid medium. At that time, the fluid medium may be changed into the bubbles. Accordingly, there is a limit in that the hot water heating unit and the circulating pump are minatured.
Therefore, in order to solve the problems involved in the prior art, it is an object of the present invention to provide an electric boiler apparatus capable of indirectly heating a fluid medium by means of a heating member.
It is another object of the present invention to provide an electric boiler apparatus capable of obtaining a high efficiency using less energy.
It is still another object of the present invention to provide an electric boiler apparatus capable of miniaturing a hot water heating unit and a circulating pump.
In order to achieve the above objects, according to one aspect of the present invention, there is provided an electric boiler apparatus capable of indirectly heating a fluid medium, the apparatus comprising: a rubber casing including a port for receiving a cool water, a port for exhausting a hot water, the ports being provided opposite to each other, and a port for receiving a supplement water, a hole formed on both sides thereof; a heat accumulator accommodated into the rubber casing, secured to the rubber casing by fixing protrusions formed on both sides, and including recessed portions formed between a left and right step and having a height higher than that of the steps; a temperature control unit, secured to a left side of the heat accumulator, for controlling a surface temperature of the heat accumulator; a temperature adjusting unit, secured to a right side of the heat accumulator, for controlling a temperature of the hot water; heating means inserted into a hole of the heat accumulator and being heated by a power; a hot water heating unit consisting of a supplement tank; a circulating pump consisting of a shading motor; and a hot water pipe.
The heat accumulator is made of metal or nonferrous metal. Preferably, the heat accumulator is made of aluminum.
The heating means comprises a positive temperature coefficient or an electric heater.
The pump is secured by inserting T-shaped protrusion formed continuously on a circumference of a body into T-shaped grooves formed continuously on an inner periphery of the shading motor.
An outer surface of the pump is plated with an anodizing coating film. The pump is made of synthetic resin.